[PATCH] drm: Only use DRM_IOCTL_UPDATE_DRAW compat wrapper forcompat X86.

[David Miller]

Ben, I'm pretty sure you're hitting this too on powerpc.  Every time a
32-bit process tries to upload cliprects it's going to fail with
-EFAULT or similar.

Nothing in userspace checks the return value for errors, etc. :-/

The only reason I caught this is because I have a debugging check on
sparc64 that makes sure that faults on kernel accesses to 32-bit
userspace never have any of the high 32-bits set.

--------------------

drm: Only use DRM_IOCTL_UPDATE_DRAW compat wrapper for compat X86.

Only X86 32-bit uses a different alignment for "unsigned long long"
than it's 64-bit counterpart.

Therefore this compat translation is only correct, and only needed,
when either CONFIG_X86 or CONFIG_IA64.

Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
---
 drivers/gpu/drm/drm_ioc32.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/drm_ioc32.c b/drivers/gpu/drm/drm_ioc32.c
index 920b72f..282d9fd 100644
--- a/drivers/gpu/drm/drm_ioc32.c
+++ b/drivers/gpu/drm/drm_ioc32.c
@@ -954,6 +954,7 @@ static int compat_drm_sg_free(struct file *file, unsigned int cmd,
 			 DRM_IOCTL_SG_FREE, (unsigned long)request);
 }
 
+#if defined(CONFIG_X86) || defined(CONFIG_IA64)
 typedef struct drm_update_draw32 {
 	drm_drawable_t handle;
 	unsigned int type;
@@ -984,6 +985,7 @@ static int compat_drm_update_draw(struct file *file, unsigned int cmd,
 			DRM_IOCTL_UPDATE_DRAW, (unsigned long)request);
 	return err;
 }
+#endif
 
 struct drm_wait_vblank_request32 {
 	enum drm_vblank_seq_type type;
@@ -1066,7 +1068,9 @@ drm_ioctl_compat_t *drm_compat_ioctls[] = {
 #endif
 	[DRM_IOCTL_NR(DRM_IOCTL_SG_ALLOC32)] = compat_drm_sg_alloc,
 	[DRM_IOCTL_NR(DRM_IOCTL_SG_FREE32)] = compat_drm_sg_free,
+#if defined(CONFIG_X86) || defined(CONFIG_IA64)
 	[DRM_IOCTL_NR(DRM_IOCTL_UPDATE_DRAW32)] = compat_drm_update_draw,
+#endif
 	[DRM_IOCTL_NR(DRM_IOCTL_WAIT_VBLANK32)] = compat_drm_wait_vblank,
 };
 
-- 
1.6.1.2.350.g88cc

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